Collector for a motor vehicle heat exchanger with a partitioning made of crossing flat strips

ABSTRACT

The invention relates to a header of a heat exchanger for motor vehicles with an at least two-part design of the header of a tube bottom and a cap, which together form, optionally with at least one further component, the housing of the header. According to the invention, it is intended that the cap and/or the tube bottom together with the respective housing wall extending around is an integral diecast part.

BACKGROUND OF THE INVENTION

The invention relates to a collector or header of a heat exchangeraccording to the preamble of claim 1.

The term header generally not only means an intermediate header or aheader on the outlet side, but also a distributor on the inlet side.

Many of such multipart headers are known. In the past, for such a headerone has generally made a cap, a tube bottom or a compartment subdivisionof sheet metal or a plate-like material, caps having been deep-drawn forexample of sheet metal. For special purpose constructions, injectionmoulded parts have already been used in the past. For example anevaporator, which is in particular also to be employed in motor vehicleair conditioning equipment, for a distributor a sandwich construction ofinjection moulded plates has been employed according to the DE-31 50 187C2, in which the chambers required in a distributor have been obtainedby corresponding groove formations.

In the following, instead of the term injection moulding the termdiecast will be used in the description of the invention, the termsdiecast and injection moulding being, however, considered to be synonymswithin the scope of the invention.

It is already known per se to make the cap and the tube bottom of aheader or a comparable structural part, such as a refrigerantdistributor (DE-A1-42 12 721), each by diecasting. The diecast materialson aluminum basis used in most cases, however, cannot be soldered norbrazed due to their high portion of silicon in aluminum alloys.Therefore, in such cases one has assembled the header or a similarstructural component by using inserted seals. This requires anadditional constructional effort and restricts the permanent closeness.

The inset of the refrigerant distributor of the DE-A1-42 12 721 is notmade as a diecast part but as an extruded piece (column 4, lines 1-3).Extruded pieces on an aluminum basis have always been able to be brazeddue to the composition of their aluminum alloys different from that ofdiecast parts.

BRIEF SUMMARY OF THE INVENTION

The object underlying the invention is to further take advantage of thepossibilities of the diecast manufacture for headers in motor vehicleheat exchangers than has been taken into account in the past.

That is, by means of an appropriate selection of the material for theinset the invention makes possible in an advantageous manner acombination of the following two aspects which has not been taken intoconsideration in the past:

On one hand, the inset is included in the soldering, preferably brazing,of the complete header.

On the other hand, the possibilities of making the form or design of theheader by producing the header of diecast are taken advantage of.

Especially preferred is the use of the alloy according to claim 20 newlydeveloped for the manufacture as a solderable or brazable diecast part.

That is, within the scope of the invention the following three aspectsare in addition particularly taken advantage of:

First aspect: The diecast manufacture is not restricted only to a plateconstruction, but can also be employed for the manufacture of tank-likebodies with a bottom and a side wall extending therearound. Such a sidewall extending around is not given from the beginning in the known plateconstruction.

Second aspect: The diecast technique makes it also possible tomanufacture filigree flat web grids which have been manufactured in thepast in a complicated assembly construction of cut out sheet metalstrips (cf. DE 195 15 526 C1, FIG. 11).

Third aspect: In evaporators, in which the header serves as adistributor on the inlet side, it is even possible to design separatesupply lines to different inlet chambers provided for a uniformdistribution to continued ducts together with the connection openingsbetween the supply lines and the respectively assigned inlet chamber inthe diecast technique within the corresponding chamber subdivision,whereby in an integral fabrication of the chamber subdivision with thecap of the evaporator, a separate cover in the cap of an arbitrarystructure is to be provided above the supply lines. This in particularcreates the possibility not given in the past to take advantage of aregion for the arrangement of the supply lines within a cross-sectionlongitudinal of the distributor, which is no longer restricted by thespace requirement of the inlet chamber on the inlet side.

The invention gives emphasis to one of the three above-mentioned aspectsand incorporates the two remaining further aspects into the invention asfurther developments.

From the DE-31 36 374 C2, it is already known per se to integrate a bodyintended as an inset into a connection case of a distributor, which, inview of its manner of construction, can possibly also be made byinjection moulding, which body itself can be finished by cutting or asan injection moulded part and combines various supply lines toindividual inlet chambers. This, however, does not mean an integralfabrication of such supply lines having an injection moulded or diecastcompartment subdivision.

As far as diecast or injection moulding, respectively, has been used inthe past within the illustrated application fields for assembling aheader, apart from the already mentioned seals adhesives have beenmainly considered as connections. However, in contrast thereto, theinvention provides, as illustrated, diecast parts for the inset andpreferably also for the casing (cf. claim 12) the shaping of whichcorresponds in many aspects to that of pre-shaped sheet metal pieces.The invention furthermore considers to combine diecast parts with sheetmetal pieces. In the present context, however, shaped sheet metal pieceshave generally been soldered by brazing. This conventional kind ofconnection by soldering, preferably by brazing, is adopted within thescope of the invention by completely or partially including diecastparts, by using a solderable or brazable alloy as a material for thediecast part in question. In a combination with sheet metal pieces beingsolder- or braze-coated on at least one side, one can then evencompletely dispense with a corresponding solder or braze coating of thediecast part in question.

The pins according to claim 2 (with the further developments of claims 3to 10 and 14) have--inter alia--the advantage that before soldering orbrazing the header a mechanically adherent pre-assembly of cap and tubebottom of the header can be effected such that by doing this the solderor braze gap can remain minimal and correspondingly the security againstleakage when soldering or brazing is maximal.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be illustrated more in detail by means of schematicdrawings and several embodiments as follows, wherein:

FIG. 1 shows a perspective outside view of a four-flow flat tube heatexchanger designed as an evaporator;

FIG. 2 shows a possible cross-section embodiment of the flat tube heatexchanger according to FIG. 1 with a first modification of theembodiment of the header;

FIG. 3 shows a cross-section corresponding to FIG. 2, however, with asecond modification of the embodiment of the header;

FIG. 4 shows a possible compartment subdivision of the header accordingto FIG. 3 made of diecast which can be inserted between the tube bottomand the cap thereof;

FIG. 5 shows a plan view on the tube bottom of a header according toFIG. 3 wherein the cap is put off, the compartment subdivision accordingto FIG. 4, however, is put on;

FIGS. 6a to 6d show detailed cross-sections of four alternatives of aconnection each of the compartment subdivision according to FIG. 4 withthe tube bottom or the cap of the evaporator according to FIG. 3; and

FIG. 7 shows a section longitudinal of a cap made as a diecast of aheader on the side of the inlet.

The flat tube heat exchanger represented in the figures has a four-flowdesign in all represented embodiments and is designed as an evaporatorof a refrigerant circulation.

This does not exclude to transfer the gist of the represented featuresalso to heat exchangers having a different number of flows, optionallyalso to heat exchangers not being designed with flat tubes and notserving as evaporators.

DETAILED DESCRIPTION OF DRAWINGS

The flat tube heat exchanger has the following general design:

A major number of typically twenty to thirty flat tubes 2 is arranged atconstant distances to each other and with aligned front sides 4. Betweenthe flat sides 6 of the flat tubes each, a zig zag fin 8 is internestedin a sandwiched fashion. A zig zag fin 8 each is furthermore arranged atthe two outer surfaces 4 of the outer flat tubes. Each flat tubecomprises internal reinforcing webs 10, which division off chambers 12in the flat tube acting as continuous ducts. Depending on the structuraldepth, a number of the chambers or ducts 12 of ten to thirty is typical.

The stated typical regions of the number of flat tubes and the chambersthereof are intended to be only a preferred number and are not intendedto be restricting.

In a motor vehicle air conditioning equipment, in the final state outerair as an external heat exchange medium flows in the direction of thearrow shown in FIG. 1 in the direction of the structural depth throughthe block arrangement of the flat tubes 2 and the zig zag fins 8.

In the evaporator, a refrigerant, such as in particularfluorohydrocarbon, serves as internal heat exchange medium which entersthe flat tube heat exchanger via a supply line 14 and exits the heatexchanger via an outlet line 16. In the refrigerant circulation, thesupply line 14 comes from the liquefier thereof. The outlet line 16leads to the condenser of the refrigerant circulation.

With an even number of flows in the heat exchanger, the distribution ofthe refrigerant on the inlet side is effected from the supply line 14 tothe individual flat tubes by a so-called distributor. On the outletside, the refrigerant is supplied as a whole to the outlet line 16.Though it is possible to assign the distribution and the collection toseparate boxes or tanks, in all embodiments both functions are combinedin a common header 18.

This header 18 is then arranged at a front side 4 of the flat tubes 2,while at the other front side 4 of the flat tubes 2, a flow reversetakes place only between each of the flows, here for example by theindividual bowls 20 illustrated in FIG. 1 or by integrating thereversing functions of such individual bowls in a common reversionheader 22 (not shown) according to the illustrated representation inFIG. 2. The individual bowls 20 according to FIG. 1, too, can beintegrated by links (not shown) to form a modular unit, if necessary.

In the borderline case of a single-flow heat exchanger, bowls 20 or thereversion header 22 would be replaced by an outlet header (not shown).

The multi-flow design means at least one flow reverse in the region ofthe individual ducts formed by the chambers 12 in each flat tube 2. In adouble-flow design, the bowl 20 or the reversion header 22 does then notneed any further intermediate chamber subdivision, it is only necessarythat a single reversion function is guaranteed. In case of a multiplereversion, at least one parting wall is necessary, which is representedin the case of a four-flow design in FIG. 2, so that in this case of afour-flow design, a double simple reversion in the respective bowl 20 orin the reversion header 22 is effected. In a design with an even greaternumber of flows, the number of parting walls 24 optionally has to beincreased.

The header 18 is basically composed of a tube bottom 26 and a cap 28,and optionally further parts for assembling the header 18 can beprovided, which are at least partially stated in the following.

The free ends of the flat tubes 2 facing away from the bowls 20 or thereversion headers 22, respectively, tightly engage the tube bottom 26 incommunication with the inner space of the header 18, which tube bottomis correspondingly provided with engaging slits as well as optionallywith internal and/or external engaging muffs.

As in the header 18, the inlet function and the outlet function of therefrigerant are combined, the header 18 requires at least a two-chamberdesign which separates an inlet side from the outlet side. For thispurpose, the chamber subdivision generally denoted with 30 comprises atleast one flat web in form of a longitudinal web 32, which separates theinlet region in the header 18 communicating with the supply line 14 froman outlet chamber 34 continuously extending longitudinally of the header18 and communicating with the outlet line 16.

In the evaporator, furthermore the supply of the refrigerant on the sideof the inlet to all flat tubes 2 has to be as uniform as possible. In aborderline case, the supplied refrigerant can be supplied to eachindividual flat tube 2 separately by a so-called distributor. In mostcases, however, the supply is effected to adjacent groups of flat tubes,in which at least some groups comprise a number of flat tubes higherthan one, wherein the number of flat tubes per group can also vary. Inthe embodiment according to FIG. 5, the same number of two flat tubesper group is provided with a total number of ten flat tubes. An owninlet chamber 36 is assigned to each group of flat tubes, which chamberdirectly communicates with the respective group of the flat tubes. Theinlet chambers 36 are divisioned off from one another in the chambersubdivision 30 by crosswise webs 38 designed as flat webs.

In a not shown double-flow evaporator, the crosswise webs 38 depart at aright angle only from one side of each of the longitudinal webs 32.

In the represented four-flow evaporator, apart from the longitudinal web32 contiguous to the outlet chamber 34, another longitudinal web 40 inparallel to this web is provided. This web is intersected at a rightangle by the crosswise webs divisioning off the inlet chambers 36 up tothe connection to the longitudinal web 32. In the elongation of thecrosswise webs 38 between the two longitudinal webs 32 and 40, betweeneach of these longitudinal webs an inner reversion chamber 42 contiguousto the respective outer inlet chamber 36 for reversing the second flowinto the third flow is divisioned off within the header 18.

In case of greater numbers of flows which are guided through the header18 with a reversion function, the number of the longitudinal webs withthe function of the longitudinal web 40 as well as the number of theinner reversion chambers 42 increase correspondingly, the reversionchambers then being furthermore internested in the crosswise directionof the header situated internally and one next to the other between theinlet chambers 36 as well as the outlet chamber 34.

The supply line 14 communicates with each of the individual inletchambers 36 via an own supply line 44 extending in the header 18, whichhas various designs in the embodiments.

In most cases, in the assembled heat exchanger the block of flat tubes 2and zig zag fins 8 is laterally terminated by a side sheet metal 46 incontact with each of the outer zig zag fins, such that the side sheetmetals 46 form an outer frame for the outer air flowing against the heatexchanger block.

The flat tubes 2, the zig zag fins 8, the tube bottom 26 and the cap 28of the header together with the optionally provided chamber subdivision10 as well as the side sheet metals 46 of the heat exchanger consist, aswell as conveniently the supply line 14 and the outlet line 16, ofaluminum and/or an aluminum alloy and are brazed including the sectionsof the line connections adjacent to the flat tube heat exchanger to formthe finished evaporator.

Without the invention being restricted thereto, in practice at least inrefrigerant evaporators for motor vehicle air conditioning equipment'saccording to FIG. 1, the supply line 14 and the outlet line 16, whichcan pass over into the header 18 via corresponding connecting sleeves,are connected to two respective connecting sleeves 48 of athermostatically controlled block valve 50. At the opposite side whichis not visible, this valve comprises two further connecting sleeves atthe side of the inlet and of the outlet.

In the following, the various embodiments are considered more in detail:

First of all in the embodiment of the matching FIGS. 3 and 4, the tubebottom 26 and the cap 28 are formed of sheet metal pre-coated withsolder or braze. The free edge of the cap here engages with an overlapon at least one side--in FIG. 3 a two-sided overlap 52 is presented--thetube bottom 26.

According to FIG. 3, the own supply lines 44 of the inlet chambers 36are integrated in a manifold pipe 54, which comprises a tube casing 56and an internal star-shaped subdivision 58, the free segments of whichform the own supply lines 44. In order to make possible that these ownsupply lines 44 join the pertaining inlet chamber 36 in each case at thesame circumferential location of the tube casing 56, the star-shapedsubdivision 58 has a helical or coil-shaped course, respectively. Therespective own supply line 44 here communicates with the related inletchamber 36 via an outlet opening 60 arranged in the tube casing 56 ofthe manifold 54. If required, the respective outlet openings 60 can alsobe designed for direct injection purposes into the inlet chambers in athrottle fashion and dimensioned, such that the pressure differencebetween the liquefying and evaporating pressure is essentially reducedto zero. In FIG. 3, an orientation of the outlet opening to the wall ofthe inlet chamber 36 is shown. The corresponding angle can be selectedas required without a direct orientation towards the chambers 12 of theflat tubes 2 being excluded.

As can be seen more in detail from FIG. 4, the chamber subdivision 30consists of the two longitudinal webs 32 and 40 as well as the crosswisewebs 38 intersecting them on an integral diecast or injection mouldedpiece, the terms diecast and injection moulding being understood assynonyms within the scope of the invention.

The term intersecting flat webs of the chamber subdivision 30 isintended to also mean the borderline case of an intersection only on oneside in the sense of the connection at a right angle of the crosswisewebs 38 to the longitudinal web 32 only on one side, which, in case of adouble-flow heat exchanger, forms the complete chamber subdivision 30.

For connecting the chamber subdivision 30 with the cap 28 as well aswith the tube bottom 26, the links of the longitudinal webs 32 and 40with the flat webs 38 are each provided with a columnar reinforcement62, which pass over at both opposing sides of the chamber subdivision 30into pins 64 tapering towards the outside and being in alignment on bothsides of the chamber subdivision with themselves and with the columnarreinforcements 62. These pins 64 are integrally designed at the diecastpart of the chamber subdivision 30 and serve as a connection with thetube bottom 26 as well as with the cap 28, in FIG. 3 a kind ofconnection being pictorialized, namely that of FIG. 6c described in thefollowing.

In FIG. 5, another alternative to the embodiment according to FIG. 4 isshown, wherein in addition to the pins 64 on both sides, supplementingpins 66 are designed on both sides between the pins 64, being steadilyor uniformly inserted in a raster fashion, which pins 66 can optionallyextend from columnar reinforcements 62 of the flat tubes, which are thennot designed at intersection points of the flat webs.

As can further be seen in FIG. 5, the raster or pattern of the pins 64and 66 is selected so as to be internested in the raster or pattern ofthe connecting points each of the flat tubes 2, so that neithermechanically a detrimental interaction of the pin connections of thechamber subdivision 30 with the tube bottom on one hand and of the flattubes 2 with the tube bottom on the other hand occurs. An eccentricinternesting is shown, which, however, can also be provided as a centricinternesting.

FIGS. 6a to 6d show, without intended to be a concluding enumeration,four preferred kinds of connection of the pins with the sheet metal ofthe tube bottom 26 and/or the cap 28.

In the alternative of FIG. 6a, the sheet metal only has to be indentedbowl-like, the corresponding pin 64 or 66 then engaging the indentation68 with its tapering end and being brazed at that location. This kind ofconnection would be an adoption of the kind of connection of the flatwebs, that is in particular of the longitudinal webs 32 and 40, thechamber subdivision 30 with the cap 28 and/or the tube bottom 26.

However, for increasing the stability, preferably the manners offastening the pins 32 and 40 with the tube bottom and the cap accordingto FIGS. 6b to 6d are used, the connection of the flat webs with thetube bottom and the cap according to FIG. 6a being maintained, in whichmanners of fastening in each case a gripping through the sheet metal ofthe tube bottom or the cap, respectively, is effected by the pins. FIG.6b shows a simple lead-through, which in turn is brazed. In FIG. 6c,according to FIG. 1 the pin lead through is headed at the outside, suchthat it forms an outer form-fitted undercutting lock. In the alternativeaccording to FIG. 6d, in addition the pin having a constant thickness inthe other embodiments, except for the conical bevel, is columnarilythickened such that at the inner side of the header 18, too, an undercutis effected, which effects a complete overgrip of the sheet metal oftube bottom and cap in connection with the heads (or headed portions) inthe sense of FIG. 6c. In the embodiments according to FIGS. 6b to 6d,too, the bowl-like shaping of FIG. 6a is adopted, however, in addition ahole for gripping through is provided in this bowl-like shaping. Thisincreases the dimensional stability of the sheet metal assembly.

In FIG. 4, furthermore one can see that in the region of the inletchambers 36, the crosswise webs 38 each are provided with anapproximately semicircular recess 70 at the top, in which the manifold54 is inserted according to FIG. 3. In its embodiment of brazablealuminum or a corresponding aluminum alloy, the brazing of the manifoldcan be effected in the described manner together with the complete heatexchanger.

The alternative according to FIG. 2 is in accordance with the embodimentaccording to FIGS. 3 and 4, except for the manifold 54 and the recesses70 adapted thereto being dispensed of. Instead, the own supply lines 44to the individual inlet chambers 36 are in addition integrally designedin the diecast part in supplementation of this diecast part of thechamber subdivision 30.

As can be seen from FIG. 2, for this purpose the header 18 comprises twolevels, seen in the extension direction of the flat tubes. In the lowerlevel, all mentioned inlet chambers 36 into the groups of flat tubes arearranged. In the upper level, in addition the own supply lines 44 extendto the chambers 36. The design of this region, as well, in an integraldiecast part is easily possible, as in the diecast part the inletchambers 36 are still open to the longitudinal side of the header 18 andthe own supply lines 44 are open on the side facing away from the flattubes 2 and are separated from the inlet chambers 36 only by a partingwall 72 separating the two levels, in which parting wall the outletopenings 60 each are arranged, the dimensions of which are the same asexplained with respect to the manifold 54.

It is appreciated that the own supply lines 44 of the inlet chambers 36are commonly fed by the refrigerant on the side of the inlet in theupstream direction, as is also the case with respect to the manifold 54.Furthermore, the own supply lines 44 are terminated each at their ends,as also goes for the free end of the manifold 54.

In the formerly described embodiments of FIGS. 2 to 6d, at least thechamber subdivision and optionally the distributor device of therefrigerant on the side of the inlet for the distribution to theindividual inlet chambers is integrated in a diecast part. This piececan principally be inserted as a separate part in a tube bottom 26 andcap 28 of the header 18 shaped of a sheet metal, the cap and the bottomtogether completely or to a major extent also forming thecircumferential surface of the header 18. The cap and/or the tubebottom, however, can be in turn an integral diecast part each. This isdescribed by means of FIG. 7 in the embodiment of which at least the cap28 itself, which is solely considered in the following, is made ofdiecast. For reasons of an easier production, the tube bottom can herebe conveniently shaped of solder or braze coated sheet metal as in theformerly described embodiments, however, as mentioned it can also be anintegral diecast part in a manner not described in detail. Theembodiment according to FIG. 7 is not to exclude the possibilitydescribed by means of FIGS. 1 to 6b to prepare the chamber subdivision30 as an own diecast part which is inserted in a cap 28 also preparedseparately by diecasting and which is optionally also placed upon a tubebottom 26 made by diecasting together with the cap 28.

Here, unlike in the formerly described embodiments, it is dispensable,if necessary, to form the chamber subdivision 30 and the own supplylines 44 to their inlet chambers 36 in a separate component. The chambersubdivision and the distributor device can rather be even completelyintegrated with the individual own supply lines 44 in the design of thecap, namely to a really high extent in the integral diecast partthereof.

Notwithstanding this possibility, the own supply lines 44 can bearranged according to FIG. 3 in a separate manifold 54 which is forexample built into the header as an own component and for exampleaccording to FIG. 4 placed upon the semicircular recesses 70 of thechamber subdivision 30. Here, cap 28, tube bottom 26, chambersubdivision 30 and manifold 54 can be separate components.

In all embodiments of the invention, in which diecast parts are takeninto account, one can do without these diecast parts themselves beingsolder coated, if the connection parts are designed with a solder orbraze coating, such as for instance the supply line 14, the outlet line16, the cap 28 in a sheet metal design as well as in a diecast partdesign, and, as already mentioned, the solder or braze coated sheetmetal of the tube bottom.

An embodiment of the cap 28 as diecast part can be for exampletransferred to the alternative according to FIG. 2, where the own supplylines 44 are only arranged in the region of the inlet chambers 36 andcan be integrated in the cap, if necessary. The own supply lines 44,however, can reach in a borderline case up to the longitudinal web 32adjacent to the outlet chamber 34 being integrated in the diecast partof the cap 28, if necessary.

The supply line 14 and the outlet line 16 are arranged at the front sideof the header 18 or the cap 28 thereof in the described embodiments, asin FIG. 1. Equally, an arrangement of at least the outlet line 16 can beprovided at the longitudinal side of the header, preferably in thecenter thereof.

FIG. 7 shows an embodiment of the cap 28, in which the fluiddistribution to the individual own supply lines 44 to the inlet chambers36 are designed in a preferred manner.

Here, a thermostatically controlled injection valve 86 is partiallyincluded in the design of the cap 28 as diecast part and thus does notconsume any own assembly space with its essential component outside theevaporator, as is still the case in the design as block valve 50 in FIG.1.

Preferably, the housing 88 of the injection valve 86 is additionallyformed by the diecast part of the cap 28.

The other components of the injection valve are formed of commerciallyavailable elements. Especially, in the neighborhood of the front side ofthe header 18 on the side of the inlet at the longitudinal side thereof,in the diecast part a thread 90 is left open, which is obtained in afinishing process by hollowing and into which an adjusting screw(setting screw) 94 can be screwed to various extents, at the same timesealing the circumference by an O-ring seal. This adjusting screw 94forms with a cavity formed at the front side thereof a receiving spacefor the valve spring 96, which is retained at its internal side by avalve cage 98, which supports a spherical valve element 100 at its frontside facing away from the valve spring, which valve element cooperateswith a valve seat 102.

The valve element is biased by the valve spring 96 into a closedposition of the valve opening 104 surrounded by the valve seat andcontrols the connecting cross-section between the supply line 14 and amixer chamber 106, which is arranged upstream of the supply lines 44 ofthe inlet openings to the inlet chambers 36. In the diecast part,furthermore a guiding extension 108 is additionally embodied, whichprojects into the mixer chamber 106 with an inclination and has adistributing function to the individual supply lines 44. A bafflefunction is taken over by the throttle function at the injection valve.

Axially opposite the thread 90 in the diecast part a further thread 110for receiving the thermohead 112 is left open, which communicates withthe outlet chamber 34. For this purpose, the thermohead is connected viaa stepped valve pin 114 with the spherical valve element 100, the valvepin having a clearance with respect to the internal opening of thethread 110, so that the flow connection between the outlet chamber 34and the thermohead is guaranteed. Depending on the temperature of theexiting refrigerant of the outlet chamber 34 impinging on thethermohead, the injection valve is more or less opened, so that anadaptation to a constant temperature determined by the screwed in depthof the adjusting screw 94 is achieved.

The supply line 14 and the outlet line 16 comprise a common connectionflange 116, which engages pocket or dead threads 120 at the outside ofthe diecast part via fastening screws 118.

What is claimed is:
 1. A header of a heat exchanger for motor vehicles,comprising:a tube bottom and a cap which together form a housing; achamber subdivision of intersecting flat webs wherein the chambersubdivision is an integral part which is inserted in the housing of theheader; and pins configured to form a connection with the tube bottom orthe cap wherein the pins start from junction points between the flatwebs of the chamber subdivision with a housing wall or intersectionpoints of the flat webs of the chamber subdivision.
 2. A headeraccording to claim 1, wherein at free edges of the chamber subdivision,pins are provided for the connection with the tube bottom as well aswith the cap.
 3. A header according to claim 2, wherein the pins for theconnection with the tube bottom and the pins for the connection with thecap are aligned.
 4. A header according to claim 1 wherein the pins atthe chamber subdivision are arranged in a centric internesting into gapsof a raster of arrangement of flat tubes in the tube bottom.
 5. A headeraccording to claim 4, wherein the flat webs of the chamber subdivisionare columnarily reinforced at the connection point of these pins.
 6. Aheader according to claim 1, wherein the junction points between theflat webs of the chamber subdivision with the housing wall extendingaround and/or intersection points of flat webs of the chambersubdivision are designed in a columnar reinforcement.
 7. A headeraccording to claim 6, wherein the columnar reinforcements pass over intopins.
 8. A header according to claim 1, wherein the pins are tapered. 9.A header according to claim 1, wherein the wall thickness of the flatwebs of the chamber subdivision is in the region of 0.6 to 1.5 mm.
 10. Aheader according to claim 1, wherein the cap or the tube bottom togetherwith each housing wall extending therearound are an integral diecastpart made of a solderable or brazable material.
 11. A header accordingto claim 10, wherein the heights of the chamber subdivision and of thehousing wall extending around are the same.
 12. A header according toclaim 10, wherein when making the cap as a diecast part, the tube bottomis shaped of a sheet metal piece and when making the tube bottom as adiecast part, the cap is shaped of a sheet metal piece.
 13. A headeraccording to claim 12, wherein the sheet metal is coated with solder orbraze on at least one side.
 14. A header according to claim 12, whereinthe housing wall extending around the cap diecast part or the tubebottom diecast part engages the sheet metal piece with a positive fit.15. A header according to claim 14, wherein:the housing wall extendingaround the cap diecast part or the tube bottom diecast part engages asoldered or brazed connection layer of the sheet metal piece.
 16. Aheader according to claim 14, wherein the housing wall extending aroundthe cap diecast part or the tube bottom diecast part engages a collarextending around the sheet metal piece.
 17. A header according to claim14, wherein the housing wall extending around the ap diecast part or thetube bottom diecast part engages a groove extending around and formed bythe sheet metal piece.
 18. A header according to claim 10, wherein thewall thickness of the housing of the header is in the region of 1.0 to2.0 mm.
 19. A header according to claim 10, wherein the wall thicknessof the housing of the header is in the region of 1.2 to 1.5 mm.
 20. Aheader according to claim 1, wherein the tube bottom, the cap, or thechamber subdivision are made of an aluminum alloy comprising aluminumand 1.6% manganese, or an aluminum alloy comprising aluminum, 0.5%silicon and 1% magnesium.
 21. A header according to claim 1, wherein:thetube bottom, the cap, or the chamber subdivision are made of aluminum oraluminum alloy.
 22. A header according to claim 1, wherein:the chambersubdivision is a solderable or brazable material.
 23. A header accordingto claim 1, wherein the wall thickness of the flat webs of the chambersubdivision is in the region of 1.0 to 1.3 mm.
 24. A heat exchanger,comprising:a header formed by a tube bottom and a cap; intersecting flatwebs separating a chamber in the header into a plurality of subchambers;a plurality of flat tubes for providing a path between the subchambers;and pins configured to form a connection with the tube bottom or thecap, wherein the pins start from junction points between the flat webswith a header wall or intersection points of the flat webs.
 25. A headerfor a heat exchanger, comprising:a header chamber formed by at least atube bottom and a cap; a diecast longitudinal web separating the headerchamber into at least an input chamber and an output chamber; at leastone diecast crosswise web formed integrally with the longitudinal web,separating the input chamber into a plurality of subchambers; and pinsextending outwardly from either side of a columnar reinforcement locatedat an intersecting point of the longitudinal web and the crosswise web.26. A header according to claim 25, wherein: the longitudinal web is asolderable or brazable material.
 27. A header according to claim 25,wherein: a plurality of ducts couple the input chamber to the outputchamber.
 28. A header according to claim 27, further comprising: meansfor coupling a supply line to at least some of the plurality of ducts.29. A header according to claim 27, further comprising: at least oneadditional longitudinal web, additionally separating the header into atleast one inner reversion chamber between the input chamber and theoutput chamber, the reversion chamber coupling at least some of theplurality of ducts with one another.
 30. A header according to claim 25,further comprising:means for fastening the pins with the tube bottom orthe cap.
 31. A header according to claim 25, further comprising:meansfor connecting the web with the tube bottom and the cap.
 32. A method,comprising:distributing a refrigerant from an input chamber of a heatexchanger header to at least one flat tube leading away from the heatexchanger header; reversing the flow of the refrigerant into at leastone other flat tube coupled to an output chamber of the heat exchangerheader; and separating the refrigerant in the input chamber of the heatexchanger header from the refrigerant in the output chamber of the heatexchanger header with intersecting flat webs, the flat webs forming theinput and output chambers by connecting with a tube bottom or cap withpins starting from junction points at intersections of the flat webs.